| Museum of Zoology - Animal Diversity Web - University of Michigan -- Gray Seal Fact sheet, economic importance, and conservation status. | |
| NOAA - Gray Seal Links to other websites, including OBIS (Ocean Biogeographic Information System). | |
| Pinnipeds.org -- Gray Seal History and status of seals, lifestyle, statistics, and birth information. | |
| Provincetown Center for Coastal Studies -- ID of Harbor, Gray, Harp, Hooded and Ringed Seals Male and female differences. Drawings and photos of seal heads. | |
| Smithsonian Museum of Natural History - Gray Seal Basic fact sheet, distribution map, length, weight, photos. |